Sheridan County, MT Insulation Payback
Sheridan County attic insulation, by the numbers
DOE classifies Sheridan County as climate zone 6, cold — a real winter that drives most of the annual energy bill here. Its recommended attic R-value for bare joists is R-60. Going from R-2 to the recommended R-60 costs roughly $3,480 installed for a typical attic (about 1,000 sq ft), and pays for itself in about 1.3 years at an estimated $2,607/year saved. Topping up the attic pays for itself fast here.
Heating vs. cooling in Sheridan County
Split it out and it's roughly $2,560 a year on the heating side, $48 on cooling. By estimated insulation savings, Sheridan County lands in the 98th percentile nationally. Zone 6 alone covers 459 counties in this dataset, and Sheridan County comes in 2nd by savings. Montana averages $2,182/year across the counties tracked here; Sheridan County comes in 19% higher.
Sheridan County's actual weather, not a national average
Sheridan County's climate figures — 9,573 heating and 296 cooling degree days a year — are read from PLENTYWOOD, MT US, 5 miles away, NOAA's nearest 1991-2020 normals station. That combined heating-and-cooling load ranks Sheridan County 50th nationally by total degree days — the 98th percentile. One local detail the R-value alone won't tell you: Sheridan County sits in moisture regime B (dry), which can affect the vapor-barrier choice.
The smaller top-up scenario
Already have a few inches up there? Topping R-11 up to R-49 runs about $2,280 for about $380/year saved — roughly 6 years to break even. Worth doing on the numbers alone.
Next steps for a Sheridan County attic
Actual quotes will vary by attic access, existing debris, and whether the job needs air sealing first. Treat the $3,480 figure above as a planning number for Sheridan County, not a bid - contractors typically charge a $600 minimum regardless of job size.
Where these figures come from
Sheridan County's R-60 target and its degree-day figures both come from named federal sources - see the methodology guide for exactly which ones. The guide to what R-value actually means explains why R-60 is the target here specifically.